Effects of raloxifene on the mammary epithelium of female rats in persistent estrus

Abstract

Objective. The aim of this study was to evaluate the morphological and morphometric alterations produced by raloxifene in the mammary epithelium of female rats in persistent estrus.Materials and methods. Twenty-one female Wistar–Hannover rats in persistent estrus induced by 1.25 mg of testosterone propionate were randomly divided into two groups: Group I (n = 10), receiving only water and used as control; Group II (experimental, n = 11), treated with 3 mg of raloxifene daily for 21 days. The first abdominoinguinal pair of mammary glands was extirpated and processed for morphological and morphometric evaluation. The data were statistically analysed using Student's t-test (p < 0.05).Results. Morphology revealed signs of epithelial atrophy, and morphometry showed a significant reduction in the mean number of ducts and alveoli in the experimental group (12.82 ± 0.42 and 2.91 ± 0.53, respectively) when compared with the control group (28.70 ± 1.15 and 7.20 ± 0.57, respectively). This difference was statistically significant, both for the ducts and for the alveoli (p < 0.001).Conclusion. The present results indicate that, at the dose and during the time of treatment used, raloxifene induced atrophy of the mammary epithelium of rats in persistent estrus.